. >> reporter: 10 months before she was shot and killed by police near the u.s. capitol, miriam carey told connecticut officers she was being electronically monitored by president obama. ( gunfire ) now investigators want ton if those delusions helped trigger thursday's police chase and shooting. overnight, investigators spent 12 hours searching carey's stamford, connecticut, apartment looking for clues. sources say in december, 2012, carey was taken for a mental health evaluation after complaining to police that she and her home were under surveillance by the white house. carey said she was a prophet, and warned that president obama planned to put the entire city of stamford under lockdown. but investigators say carey never made any direct threats against the president and was not known to the secret service until she showed up yesterday in a black sports coupe and tried to ram a barricade at the white house. carey died a short time later after police chased her to the capitol, surrounded her car, and opened fire. her one-year-old daughter, who was in the car du